Multiple filter elements with movable flushing assembly

ABSTRACT

A multiple element filter system comprising a filter housing defining a water inlet for water to be filtered, a filtered water outlet, a plurality of cylindrical filter elements, each defining upstream and downstream surfaces, disposed in the filter housing such that the upstream surfaces communicate with the water inlet and the downstream surfaces communicate with the filtered water outlet, and a flushing assembly including a movable flushing communication member arranged for selectable flushing communication with the upstream surfaces of each of the plurality of filter elements and apparatus for selectable coupling of the communication member to a flush drain at atmospheric or relatively low pressure.

FIELD OF THE INVENTION

The present invention relates to filtering systems and more particularlyto filtering systems employing cylindrical filter elements.

BACKGROUND OF THE INVENTION

Filtering systems including cylindrical filter elements are shown anddescribed in the following patents and patent applications of thepresent applicant:

U.S. Pat. Nos. 4,026,806; 4,045,345; 4,067,812; 4,207,181; 4,624,785

U.S. patent applications 623,353, now U.S. Pat. No. 4,681,681; 647,093,now abandoned.

Israel patent application Nos. 71674 and 73923

In filtering systems of the general type described hereinabove, periodiccleaning of the filter elements is required and is normally achieved byopening the filter housing, removing the filter element from the housingand flushing it with a stream of water.

In self-flushing systems such as the type described and claimed in U.S.Pat. No. 4,045,345 having a single filter element, such cleaning isaccomplished automatically, without the need to open the filter housing.

SUMMARY OF THE INVENTION

The present invention seeks to provide a multiple element filter systemwherein cleaning of the filter elements may be accomplished withoutopening the filter housing and removing the elements.

There is thus provided in accordance with a preferred embodiment of thepresent invention a multiple element filter system comprising a filterhousing defining a water inlet for water to be filtered, a filteredwater outlet, a plurality of cylindrical filter elements, each definingupstream and downstream surfaces, disposed in the filter housing suchthat the upstream surfaces communicate with the water inlet and thedownstream surfaces communicate with the filtered water outlet, and aflushing assembly including a movable flushing communication memberarranged for selectable flushing communication with the upstreamsurfaces of each of the plurality of filter elements and apparatus forselectable coupling of the communication member to a flush drain atatmospheric or relatively low pressure.

In accordance with an embodiment of the invention, the flushing assemblyincludes means for providing relative rotation between the flushingcommunication member and the plurality of filter elements about a firstaxis and rotation of each filter element about its own longitudinal axiswhich lies parallel to the first axis.

In accordance with a preferred embodiment of the present invention, theupstream surface is the outer surface, the flushing communication memberis centrally located with respect to the plurality of filter elementsand they are mounted for selectable relative rotation whereby thecommunication member selectably engages the outer surfaces of theindividual elements.

Further in accordance with a preferred embodiment of the inventionmanually operative apparatus is provided exterior of the filter housingfor selectably rotating the flushing communication member intocommunication with the outer surfaces of the individual elements and forproviding rotation of the individual filter elements while incommunication with the communication member.

Additionally in accordance with an embodiment of the invention, thecommunication member is formed with an elongate engagement flush inletslot which is brought into flushing communication with the outersurfaces of the individual elements by rotation of the communicationmember.

Further in accordance with an embodiment of the invention the apparatusexterior of the filter housing for rotating the communication member andthe elements comprises communication member extension means coupled tothe communication member and element extension means coupled to theindividual element, for providing rotation thereof about theirrespective longitudinal axes from a location external of the filterhousing.

Additionally in accordance with this embodiment of the invention, thereis provided a rotation crank handle for providing manually drivenrotation of the individual element extension means, and a handle supportonto which the rotation handle is mounted, the handle support beingcoupled to the communication member extension means and rotatabletherewith such that when the handle is located for engagement with agiven element for rotation thereof, the inlet slot of the communicationmember is in operative flushing communication with the outer surface ofthat element, whereby rotation of the element causes the entire outersurface of the element to be scanned by the inlet slot, the pressurerelationship being such that when the communication member is coupled tothe flush drain, a positive pressure gradient exists across the portionof the element in flushing communication with the slot causing dirt fromthe element to be flushed into the slot and out the drain.

According to a preferred embodiment of the invention the apparatus forselectable coupling of the communication member to a flush drain atatmospheric or relatively low pressure comprises means for blocking thewater outlet during flushing.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description taken in conjunction with thedrawings in which:

FIG. 1 is a side sectional illustration of a filter system constructedand operative in accordance with an of the present invention;

FIG. 2 is a horizontal sectional illustration of the system of FIG. 1taken along lines II--II in FIG. 1, it being noted that FIG. 1 is takenalong the lines I--I in FIG. 2;

FIG. 3 is a top view illustration of the system of FIGS. 1 and 2,corresponding in operative orientation to FIG. 2;

FIG. 4 is a side sectional illustration of a preferred embodiment of theinvention in a non-flushing orientation; and

FIG. 5 is a side sectional illustration of the embodiment of FIG. 4 in aflushing orientation.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to FIGS. 1-3 which illustrate the filter system ofan embodiment of the present invention. The filter system comprises asealed filter housing 10, typically including top and bottom portions 12and 14 which are mounted on a support base 16. Disposed inside the thefilter housing 10 are a plurality of filter elements 18, preferably inthe form of stacks 18 of filter discs, which are operative to filterwater passing therethrough. Examples of suitable filter discs and stacksfor this purpose appear in the following patents and patent applicationsof the present applicant:

U.S. Pat. Nos. 4,026,806; 4,045,345; 4,067,812; 4,207,181; 4,624,785

U.S. patent application Ser. Nos. 623,353; 647,093;

Israel patent application Nos. 71674 and 73923

As seen in the drawings, the elements 18 are arranged to have theirrespective longitudinal axes generally symmetrical about the center ofthe housing. Located centrally of the stacks is a flushing communicationmember 20, which is typically a pipe sealed at one end and having alongitudinal slot 22 formed therein.

It is a particular feature of this embodiment of the invention that thecommunication member 20 and the elements 18 are all rotatable abouttheir individual longitudinal axes. It may be appreciated that therotatability of member 20 provides selectable communication of slot 22with the outer surfaces of each of elements 18, while the rotatabilityof each of elements 18 permit the slot 22, when in engagement with agiven element 18 to effectively scan the entire outer surface of theelement as it is rotated.

In the illustrated embodiment of the invention, a water inlet 24, forwater to be filtered, is provided at the side of the housing, such thatwater to be filtered is provided at the outer surface of each of thefilter elements 18. The interior surfaces of each of the elementscommunicate via a suitable manifold 26, which does not impede rotationof the elements about their longitudinal axes, with a filtered wateroutlet 28.

The engagement member 20 communicates via a manually or otherwiseoperable valve 30 with the outside atmosphere, or any relatively lowpressure receptacle.

It is seen in FIGS. 1 and 3 that each of the elements 18 is providedwith a suitably splined extension 32 which passes through the housing 10via a suitable sealing bushing 34 or the like and which permits rotationof the element 18 about its longitudinal axis from outside the housing10. The engagement member 20 is provided with a similar extension 35 forrotation of engagement member 20 about its own axis.

A rotation crank handle 36 having an associated socket 38 arranged forremovable engagement with extensions 32 is rotatably mounted on a handlesupport 39. Handle support 39 is in turn mounted for rotation togetherwith extension 35, such that the location of the socket 38 iscoordinated with the orientation of the slot 22 of the communicationmember 20, whereby when socket 38 engages the extension 32 of a givenelement 18, the slot 22 of the communication member 20 is in operativeengagement with the outer surface of that element.

Handle support 39 is provided with a pivotal mounting about an axis 41perpendicular to the longitudinal axis of the communication member 20,so as to enable socket 38 to be removeably engaged with the variousextensions 32.

The flushing operation of the filter system just described may beunderstood as follows: When it is desired to flush the system, valve 30is opened, thus creating a pressure differential across the portion ofthe filter element which is in communication with slot 22 of thecommunication member. The high pressure side being the interior of eachelement which is at the pressure of the filtered water outlet, normallywell above atmospheric pressure and the low pressure side being theinterior of the engagement member which may be at atmospheric pressure.

It is noted that even if the engagement of the slot 22 with the outersurface of the element 18 is not particularly close, the outflow ofunfiltered water from the interior of the filter housing need not besignificant and can be helpful in removing dirt from the element underthe pressure differential to enter the slot 22. The flow of unfilteredwater from the interior of the filter housing 10 through slot 22 alsoincreases the pressure differential due to the venturi effect.

It is a particular feature of the invention that a single rotation ofthe handle in engagement with each extension 32 causes the entiresurface of an element 18 to be "scanned" and thus cleaned by slot 22.The arrangement of the handle support 39 ensures that the stack beingrotated is the one in engagement with slot 22, such that the scanning ofall of the stacks can be accomplished in a matter of minutes with simplehand movements and without requiring skilled workers.

It is appreciated that instead of rotating the engagement member 20, theelements 18 may be revolved thereabout. Similarly, in principle, theslot 22 could be revolved around the elements which could remainstationary. Also, a system of this type could be adapted for anarrangement wherein the inner surfaces of the stacks are at the upstreamside. Nevertheless, the described embodiment is believed to be the mostpractical and efficient in construction and use.

Reference is now made to FIGS. 4 and 5 which illustrate a preferredembodiment of the present invention. The embodiment of FIGS. 4 and 5 isidentical to that of FIGS. 1-3 in all relevant respects with theexception of those described specifically hereinbelow. The descriptionof FIGS. 1-3 is to be considered equally applicable to FIGS. 4 and 5with the exception of valve 30 and connection between manifold 26 andoutlet 28.

In the embodiment of FIGS. 4 and 5, valve 30 is replaced by a valve 40,such as a ball valve, which may be operated from the exterior of thefilter housing 10, as by a suitable handle (not shown). Valve 40 governsthe communication between communication element 20 and the outsideatmosphere or any relatively low pressure receptacle on the one hand,and between manifold 26 and filtered water outlet 28 in a mutuallyexclusive manner.

Thus, when valve 40 is positioned in a first position, during normalfilter operation, as illustrated in FIG. 4, manifold 26 communicateswith outlet 28, permitting the outflow of filtered water from the filtersystem. As seen in FIG. 4, when valve 40 is positioned in this firstposition for normal filter operation, communication betweencommunication element 20 and the outside atmosphere at outlet 42 isprevented by valve 40.

When valve 40 is positioned in a second position, for flushing, asillustrated in FIG. 5, water communication is provided betweencommunication element 20 and the outside atmosphere through outlet 42.At the same time, communication between manifold 26 and outlet 28 isprevented. This causes a pressure buildup at the interior surface of thefilter elements 18 and increases the pressure gradient across theportion of the filter elements in communication with the slot 22, thusenhancing the efficiency of flushing. Effectively, the downstream,inner, surface of the filter elements is brought nearly up to theupstream, high input pressure to the filter system.

It will be appreciated by persons skilled in the art that the presentinvention is not limited by what has been particularly shown anddescribed hereinabove. Rather the scope of the present invention isdefined only by the claims which follow:

I claim:
 1. A multiple element filter system comprising:a filter housingdefining a water inlet for water to be filtered; a filtered wateroutlet; a plurality of cylindrical filter elements, each definingupstream and downstream surfaces, disposed in said filter housing suchthat during filtering operation said upstream surfaces communicate withsaid water inlet and said downstream surfaces communicate with saidfiltered water outlet; a flushing assembly including a movable flushingcommunication member arranged for selectable flushing communication withsaid upstream surfaces of each of said plurality of filter elements; andmeans for selectable coupling of said communication member to a flushdrain, and wherein said communication member and said plurality offilter elements are mounted for selectable relative rotation wherebysaid communication member selectably engages the outer surfaces ofindividual ones of said plurality of filter elements.
 2. A filter systemaccording to claim 1 and wherein said upstream surface is the outersurface.
 3. A filter system according to claim 1 and wherein saidcommunication member is centrally located with respect to said pluralityof filter elements.
 4. A filter system according to claim 1 and whereinsaid communication member is formed with a communication inlet slotwhich is brought into communication with the outer surfaces ofindividual ones of said plurality of filter elements by rotation of saidcommunication member.
 5. A multiple element filter system comprising:afilter housing defining a water inlet for water to be filtered; afiltered water outlet; a plurality of cylindrical filter elements, eachdefining upstream and downstream surfaces, disposed in said filterhousing such that during filtering operation said upstream surfacescommunicate with said water inlet and said downstream surfacescommunicate with said filtered water outlet; a flushing assemblyincluding a movable flushing communication member arranged forselectable flushing communication with said upstream surfaces of each ofsaid plurality of filter elements; and means for selectable coupling ofsaid communication member to a flush drain, and wherein each individualone of said plurality of filter elements is rotatably mounted.
 6. Afilter system according to claim 5 and wherein said upstream surface isthe outer surface.
 7. A filter system according to claim 5 and whereinsaid communication member is centrally located with respect to saidplurality of filter elements.
 8. A multiple element filter systemcomprising:a filter housing defining a water inlet for water to befiltered; a filtered water outlet; a plurality of cylindrical filterelements, each defining upstream and downstream surfaces, disposed insaid filter housing such that during filtering operation said upstreamsurfaces communicate with said water inlet and said downstream surfacescommunicate with said filtered water outlet; a flushing assemblyincluding a movable flushing communication member arranged forselectable flushing communication with said upstream surfaces of each ofsaid plurality of filter elements; and means for selectable coupling ofsaid communication member to a flush drain, and wherein said flushingassembly comprises means exterior of said filter housing for selectablyrotating said communication member into communication with the outersurfaces of at least one of said plurality of filter elements and forproviding rotation of said at least one of said plurality of filterelements while said at least one of said plurality of filter elements isin communication with said communication member.
 9. A filter systemaccording to claim 8 and wherein said upstream surface is the outersurface.
 10. A filter system according to claim 8 and wherein saidcommunication member is centrally located with respect to said pluralityof filter elements.
 11. A multiple element filter system comprising:afilter housing defining a water inlet for water to be filtered; afiltered water outlet; a plurality of cylindrical filter elements, eachdefining upstream and downstream surfaces, disposed in said filterhousing such that during filtering operation said upstream surfacescommunicate with said water inlet and said downstream surfacescommunicate with said filtered water outlet; a flushing assemblyincluding a movable flushing communication member arranged forselectable flushing communication with said upstream surfaces of each ofsaid plurality of filter elements; and means for selectable coupling ofsaid communication member to a flush drain, wherein said communicationmember is formed with a communication inlet slot which is brought intocommunication with the outer surfaces of individual ones of saidplurality of filter elements by rotation of said communication member,and wherein said flushing assembly comprises: communication memberextension means coupled to said communication member; and elementextension means coupled to individual ones of said plurality of filterelements, for providing rotation of each individual one of saidplurality of filter elements about its own longitudinal axis from alocation external of said filter housing.
 12. A filter system accordingto claim 11 and wherein said flushing assembly also comprises:a crankhandle for providing manually driven rotation of said element extensionmeans; and crank handle support means onto which said crank handle ismounted, said crank handle support means being coupled to saidcommunication member extension means and being rotatable therewith suchthat when said crank handle is located for engagement with a given oneof said plurality of filter elements for rotation thereof, saidcommunication inlet slot of said communication member is in operativecommunication with the outer surface of said given one of said pluralityof filter elements, whereby rotation of said given one of said pluralityof filter elements causes substantially the entirety of the outersurface of said given one of said plurality of filter elements to bescanned by said communication inlet slot, the pressure relationshipbeing such that when said communication member is coupled to the flushdrain, a positive pressure gradient exists across the portion of saidgiven one of said plurality of filter elements being in flushingcommunication with said communication inlet slot, causing dirt from saidgiven one of said plurality of filter elements to be flushed into saidcommunication inlet slot and out said flush drain.
 13. A filter systemaccording to claim 11 and wherein said upstream surface is the outersurface.
 14. A filter system according to claim 11 and wherein saidcommunication member is centrally located with respect to said pluralityof filter elements.
 15. A multiple element filter system comprising:afilter housing defining a water inlet for water to be filtered; afiltered water outlet; a plurality of cylindrical filter elements, eachdefining upstream and downstream surfaces, disposed in said filterhousing such that during filtering operation said upstream surfacescommunicate with said water inlet and said downstream surfacescommunicate with said filtered water outlet; a flushing assemblyincluding a movable flushing communication member arranged forselectable flushing communication with said upstream surfaces of each ofsaid plurality of filter elements; and means for selectable coupling ofsaid communication member to a flush drain, and wherein said flushingassembly includes means for providing relative rotation between saidcommunication member and said plurality of filter elements about a firstaxis and rotation of each individual one of said plurality of filterelements about its own longitudinal axis which lies parallel to saidfirst axis.
 16. A filter system according to claim 15 and wherein saidupstream surface is the outer surface.
 17. A filter system according toclaim 15 and wherein said communication member is centrally located withrespect to said plurality of filter elements.
 18. A multiple elementfilter system comprising:a filter housing defining a water inlet forwater to be filtered; a filtered water outlet; a plurality ofcylindrical filter elements, each defining upstream and downstreamsurfaces, disposed in said filter housing such that during filteringoperation said upstream surfaces communicate with said water inlet andsaid downstream surfaces communicate with said filtered water outlet; aflushing assembly including a movable flushing communication memberarranged for selectable flushing communication with said upstreamsurfaces of each of said plurality of filter elements; and means forselectable coupling of said communication member to a flush drain, andwherein said means for selectable coupling of said communication memberto said flush drain comprises means for blocking said water outletduring flushing.
 19. A filter system according to claim 18 and whereinsaid upstream surface is the outer surface.
 20. A filter systemaccording to claim 18 and wherein said communication member is centrallylocated with respect to said plurality of filter elements.